Had it and gave it away. Alarm on that thing is a no go, since it only vibrates. After a while u get used to it and vibration won't wake u up. Sleep tracking is only available at night, can't track naps or sleeps during the day.
As with any step tracker, this one falls short as well. Can't count steps properly. But is I hear it, this is the problem with all bands.
Now, battery is awesome. I used mine for more then a month every day, and battery didn't die. It was at 70+% when I gave it away. Most claim it can last for 3 months. I believe it
If these aren't a big issue for you, I would get it. It is pretty cheap, but nevertheless awesome gadget. Install modded app on you android device, you can find it on xiaomi forums. Gives u better results and control over the band.